Session Information
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose: African American (AA) patients with rheumatoid arthritis (RA) have worse Health Assessment Questionnaire (HAQ) scores and increased disease activity clinically compared to Caucasian (CAU) RA patients. Serologically, AA RA patients have a higher reported prevalence of antinuclear antibody (ANA) and anti-SSA compared to CAU RA patients in two established unmatched RA cohorts. However, no matched studies have been performed. In addition, RA and Sjogren’s Syndrome can co-exist and this joint pathology is associated with worse clinical manifestations and increased ANA and anti-SSA positivity. We hypothesize that the increased disease activity of RA in AAs may be linked to an increased frequency of ANA and anti-SSA antibodies, causing increased disease activity and more severe RA in AA patients.
Methods: Plasma samples were assayed from matched AA and CAU RA patients in the Rheumatoid Arthritis Comparative Effectiveness Research (RACER) cohort at the University of Pittsburgh. Patients were matched for variables including age, gender, disease duration, and RF and Cyclic Citrullinated Peptide (CCP) antibody positivity. ANA testing was performed using Indirect Immunofluorescence and titers of ≥ 1:80 were classified as positive. Samples also underwent specific autoantibody testing, including anti-SSA testing, with the Bioplex 2200 Multiplex Bead Assay and titers ≥ 1:1.9 were considered positive. Differences in autoantibody prevalence between AA and CAU RA patients were assessed using chi-square and Fisher’s exact tests.
Results: AA RA patients (N=94) were matched with CAU RA patients (N=93) for age, BMI, gender, RF positivity, anti-CCP positivity, and disease duration (Table 1). Anti-SSA was significantly more prevalent in the AA RA patients (11.70% vs. 3.23%; p=0.021). AA RA patients also had a higher prevalence of ANA (21.28% vs. 10.75%) and higher prevalences of systemic lupus associated antibodies including anti-RNP, anti-SM/RNP, and anti-chromatin compared to CAU RA patients (Table 2).
Conclusion: The increased disease severity observed in AA RA patients compared to CAU RA patients may be mediated by an increased prevalence of a serologically unique subset of RA patients who are ANA and anti-SSA positive.
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Table 1: RACER Demographic Data |
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African American (N=94) |
Caucasian (N=93) |
P-value |
|
Mean Age (years) |
60.39 |
58.72 |
0.394 |
|
Mean BMI (Kg/M2) |
31.04 |
29.54 |
0.243 |
|
Female (%) |
93.50% |
95.60% |
0.747 |
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RF Positive |
77.20% |
82.80% |
0.363 |
|
Anti-CCP Positive |
75.00% |
76.30% |
0.864 |
|
Mean Disease Duration (Months) |
14.00 |
13.04 |
0.520 |
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Table 2: Autoantibody prevalence in AA and CAU Patients |
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AA % Positive (N=94) |
CAU % Positive (N=93) |
P-value |
|
ANA (≥1:80) |
21.28% (20/94) |
10.75% (10/93) |
0.095 |
|
Anti-SSA |
11.70% (11/94) |
3.23% (3/93) |
0.021 |
|
Anti-SSB |
4.26% (4/94) |
1.08% (1/93) |
0.180 |
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Anti-SSA AND/OR Anti-SSB |
12.77% (12/94) |
4.30% (4/93) |
0.021 |
|
Anti-Double Stranded DNA |
4.26% (4/94) |
6.45% (6/93) |
0.523 |
|
Anti-Smith |
0.00% |
0.00% |
— |
|
Anti-Smith/Anti-Ribonucleoprotein |
3.19% (3/94) |
1.08% (1/93) |
0.317 |
|
Anti-Ribonucleoprotein |
6.38% (6/94) |
4.30% (4/93) |
0.480 |
|
Chromatin |
4.26% (4/94) |
2.15% (2/93) |
0.103 |
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Ribosomal P |
0.00% |
0.00% |
— |
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Centromere B |
0.00% |
2.15% (2/93) |
0.157 |
|
Anti-Topoisomerase 1 (Scl-70) |
1.06% (1/94) |
0.00% |
0.317 |
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Anti-histidyl tRNA synthetase (Jo-1) |
0.00% |
0.00% |
— |
To cite this abstract in AMA style:
Sevco T, Landsittel DP, Shen C, Rabin B, Moreland LW. Increased Prevalence of Anti-Nuclear and Anti-SSA Autoantibodies in African American Rheumatoid Arthritis Patients Versus Matched Caucasian Rheumatoid Arthritis Patients [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/increased-prevalence-of-anti-nuclear-and-anti-ssa-autoantibodies-in-african-american-rheumatoid-arthritis-patients-versus-matched-caucasian-rheumatoid-arthritis-patients/. Accessed .« Back to 2015 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/increased-prevalence-of-anti-nuclear-and-anti-ssa-autoantibodies-in-african-american-rheumatoid-arthritis-patients-versus-matched-caucasian-rheumatoid-arthritis-patients/